Purpose: To elucidate the association oral malodor with the levels of periodontopathic bacteria in saliva and tongue coating of periodontitis patients with oral malodor. Materials and Methods: In 25 periodontitis patients, the organoleptic test (OLT) was performed, the levels of volatile sulfur compounds (VSCs) were measured, tongue coating (TC) score was determined, and periodontal parameters and the proportions of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Treponema denticola, Tannerella forsythia and Prevotella intermedia in the saliva and the tongue coating were evaluated. Results: The proportions of T. denticola and T. forsythia in the saliva of patients with an OLT score ? 2 were significantly higher than those with OLT scores 2. The proportion of P. gingivalis in the saliva significantly correlated with periodontal parameters, whereas T. denticola and T. forsythia levels in the tongue coating correlated with VSC levels. However, the five periodontopathic bacteria were found in the tongue coating at levels approximately 12 times lower than in the saliva. Conclusions: The findings suggest that the levels of T. denticola and T. forsythia in the saliva of periodontitis patients correlate with oral malodor, and that the prevalence of P. gingivalis in the saliva is related to periodontitis. Periodontopathic bacteria in the tongue coating contribute minimally to oral malodor in periodontitis patients. Schlagwörter: oral malodor, periodontopathic bacteria, saliva, tongue coating